基于矢量控制的环流抑制策略及仿真建模

Circulation Suppression Strategy and Simulation Modeling Based on Vector Control

多逆变器并联可以提高系统的功率等级和可靠性,已在大功率的逆变器上得到广泛应用。但逆变器并联存在因载波相位不一致引起的环流问题,会增加系统的损耗。本文首先分析了环流产生的机理,通过对逆变器输出电压进行失量分析,推导出载波相位差与环流之间的关系表达式,并得到环流开关分量的特性。然后,在分析的基础上提出了一种载波相位补偿的控制策略,该策略能有效改善对开关环流的控制能力,对因载波相位不一致产生的环流起到显著抑制效果。采用PI控制电压外环,无差拍控制电流内环的双闭环控制策略,保证了逆变器系统的正常稳定运行。最后,仿真结果验证了本文所提出的控制策略的有效性和可行性。最后,通过MATLAB/Simulink仿真与搭建实物样机并进行相应实验,验证了理论分析的可行性。

Parallel connection of multiple inverters has been widely used in high-power inverters,because of improving the power level and reliability of the system.However,there was a circulating current problem caused by Phase inconsistency in parallel inverters,which could increase system losses.Through vector analyzing of inverter output voltage,and obtaining the characteristics of circulating current switching components,this article first analyzes the mechanism of circulating current,and deduces the relationship between carrier phase difference and circulating current.Then,basing on the aboveanalysis,a control strategyfor carrier phase compensation was proposed,which can effectively improve the control ability of switching circulation and can significantly suppress the circulation caused by inconsistent carrier phase.The dual closed-loop control strategy of Pl control voltage outer loop and deadbeat control current inner loop ensures the normal and stable operation of the inverter system.Finally,the feasibility of the theoretical analysis was proved by the simulation of MATLAB/Simulink,the establishment of a prototype and the corresponding experiments.